Hyaluronic Acid – A Key Molecule in Skin Aging Hyaluronic acid is a naturally occurring substance in the human body. It occurs at places where connective tissues are present and is also present in the extracellular space in the dermal and epidermal layers of the skin. Due to its gel-like structure and the property of retaining water it is responsible for maintenance of lubrication of the skin and thus it helps the skin look younger and wrinkle-free. It is therefore